I read the textbook, and I am still struggling to fully understand what the difference is between the two
HBox containers are horizontal and on the top or bottom, whilst VBox containers are vertical and on the left or right.
They are both containers of nodes, but they differ in how the nodes are displayed. Your nodes (botton, label, etc.) appears on a row in Hbox, while they will appears on a column in VBox.
Here's the source: https://docs.oracle.com/javafx/2/layout/builtin_layouts.htm